The present application relates to directing the flow of particulates in a particulate laden fluid in a downhole environment.
Particulates are often utilized in various wellbore operations. For example, after a wellbore is drilled, it may often be necessary to fracture the subterranean formation to enhance hydrocarbon production, especially in shale formations that typically have high closure stresses. Access to the subterranean formation can be achieved by first creating perforations in the casing or liner that extends through the cement sheath surrounding the casing or liner (when present) and, in some instances, into the formation. Then, fractures in the subterranean formation may be created or extended from the perforations (e.g., by hydraulic fracturing or slickwater fracturing). Generally, proppants are then introduced into the fractures to form proppant packs that hold open the fractures and maintain fluid flow therethrough after the fracturing operation is completed. In hydrocarbon production operations, the propped fractures provide conduits for the hydrocarbons to flow from the subterranean formation to the wellbore and eventually to the surface.
Because the proppant packs hold open the fractures during production, the distribution of the proppants to the various fractures during the fracturing operation impacts hydrocarbon production. That is, homogenous proppant distribution extending deep into the formation for each of the plurality of fractures is preferred to maximize hydrocarbon production. However, typically in practice, the proppant distributes heterogeneously between the fractures and, often, only a small percentage of fractures contain proppant packs that extend deep into the formation. Heterogeneous proppant distribution often hydrocarbon yields significant hydrocarbon production for a shorter amount of time that, then, declines rapidly. This is most often observed in shale and other very low permeability formations with high closure pressures. Enhancing hydrocarbon production after the decline typically involves refracturing, which can be costly and time consuming.
One method for achieving a more homogeneous proppant distribution includes forming proppant packs in a sequential subset of fractures. For example, a packer or bridge plug may be used between subsets of fractures to place proppant in that subset of fractures. Then, the packer or bridge plug is moved or removed and another subset of fractures is isolated for proppant placement. However, this procedure is time consuming and costly.
In some instances, a crossover tool may be used in conjunction with packer or bridge plug to direct fluid flow and, consequently, particulate flow in a radially outward direction to enhance particulate flow into the perforations and fractures. However, because of this significant change in direction (about a 90° diversion), portions of the crossover tool are subject to significant wear from the abrasive proppant particulates. In addition, the crossover tool may perform several other tasks while the proppant laden fluid is being pumped through it. For example, the crossover tool typically contains longitudinal circulation ports through which fracturing fluids that are not received into the formation after exiting the crossover are transmitted back to the surface. If the crossover tool is worn away such that the proppant laden fluid achieves fluid communication with the circulation ports in the crossover, the proppant laden fluid will enter the circulation ports in the crossover and travel back to the surface without delivering the proppant to the formation. Then, the crossover tool must be replaced, which is costly and time consuming.
Therefore, directing particulate flow in a downhole environment may be useful for enhancing proppant pack homogeneity and mitigating abrasive wear to increase the lifetime of wellbore tool.